I'd say call Blue Ox. I we have Brake Buddy, similar concept. To me, it's a Ford/Chevy debate I don't want to play into since I believe the quality is equal. The BB Vantage Select we have has three adjustments: Air Pressure, Braking Sensitivity, and Full or Proportional. Those govern When, How, and How Hard to apply the toad brakes.
Does the Blazer have the common vacuum-assisted "power brakes" or the new "active braking system?" If it's got Active/smart brakes, the rules might be different than for traditional brakes. I'd expect (at least with BB) to need more PSI to get more apply pressure to help stop Blazer's extra weight, but the system should still apply. Our first BB was a "Classic" that didn't offer Proportional braking, only "Full" and Full is what I still use. With sensitivity fairly high, like 5 on a scale of 8, and Full Braking, I can see it kick in on the monitor and feel the slowing when I brake firmly or sharply.
But I DO know that BB doesn't want floor mats in place. Also found the seat needs to be as close to the brake pedal AS the unit can fully retract its pusher arm and still have a little breathing room. By that I mean less than 1/2" and I'm usually at around 1/4".
WinTasca 29B is a very heavy "29-foot" coach, probably as heavy as our 31-foot Jayco, maybe more. I replaced the front brakes with the bigger ones Ford started using on 2008 and newer model years. Bought a "take-off" axle and brakes from Quigley Motors (Quigley 4x4) in Pennsylvania. If your axle (including ball joints and bushings) is in good shape, the late model brakes will install in place of your smaller ones. I opted to change it all out, and that provided their later model Radius Arm.
With the bigger brakes, and Brake Buddy in the toad, the braking I want/need is always there. That was not the case with the OEM front brakes on the E450, and those brakes had been totally rebuilt. Rotors surfaced, new pads, rebuilt calipers, new hoses. Simply NO comparison to the feel and performance of the later model front brakes.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB